How to add internal PDF links inside a table using Prawn and Prawn table

On a recent project we needed to generate a PDF using Prawn. The PDF has links from a list of contents into a table. The normal way (when not using a table) for adding internal links is to do the following:

Here we link to hello30 which will be somewhere in the middle of the table. The trouble is that we generate our data before it's being laid out so it's not immediately obvious where to make our call to add_dest.